PartnerNOC

Yes, but I am not sure if that will work with Plesk v7.x. If you login to the WHM >> Transfers >> Copy multiple accounts from another server, you'll see: (Pl*sk) 1.x, 2.x, 5.x, 6.x. Give it a shot; might work

It will work, so long as you do not (read:NOT) have subdomains on the Plesk server (Reloaded). it will also mess up any databases, so you will have to go through and edit any config files that make calls to them (Plesk does not use a prefix for their user databases, whereas CPanel prefixes them all with the CPanel username).
I sent a question to CPanel asking if they were planning on updating their migration manager to support more recent builds of Plesk (at Chirpy's suggestion), and have not yet received a reply... of course, they have not closed it either, so I'm remaining optimistic that they will have an answer for me soon.
Be glad you are getting off Plesk now, instead of after updating to 8.0... we updated at the suggestion of sw-soft (since 7.5.4 would no longer be supported and we needed them to fix a module), and it totally screwed the server... skyrocketting server loads, undelivered mail, Apache fails...
The sooner I can get the last of my sites off Plesk and onto Cpanel, the happier I'll be.

Of course, without updated Apache support, it could still turn into an ugly situation.